Self-shading by optical or thermal control of transmittance with liquid crystals doped with push-pull azobenzene

Self-switching smart windows, which can be switched between the transparent and opaque states by ambient conditions, have applications in buildings, automobiles, and switchable sunglasses. In particular, technologies for transmittance control without light scattering are highly desirable owing to their ability to control the throughput of sunlight and solar heat through a window without blocking the view. In this study, a self-shading window based on liquid crystals doped with push-pull azobenzene with a haze-free opaque state for transmittance control is demonstrated. For the realization of the haze-free opaque state (or a low-transmittance state), the isotropic phase was used, which can be induced either thermally or optically.